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Abstract:

According to one embodiment, a carbon fiber reinforced shaped product
including a metal plate has a flat plate and at least one projection. The
flat plate is formed of a sheet material including a carbon fiber
reinforced thermoplastic resin, and includes a first flat surface and a
second flat surface. The at least one projection is formed of a
thermoplastic resin from the sheet material. The flat plate includes a
metal plate provided therein and covering a flat area corresponding to
the at least one projection.

Claims:

1. A carbon fiber reinforced shaped product comprising: a flat plate
comprising a first flat surface, a second flat surface, and a sheet
material comprising a carbon fiber reinforced thermoplastic resin; and at
least one projection projecting from the second flat surface of the flat
plate, wherein the projection comprises the carbon fiber reinforced
thermoplastic resin from the sheet material; and the flat plate comprises
a metal plate provided therein and covering a flat area corresponding to
the at least one projection.

2. The product of claim 1, comprising a plurality of projections
projecting from the second flat surface of the flat plate, wherein the
metal plate covers a plurality of flat areas corresponding to the
plurality of projections.

3. The product of claim 1, wherein the flat plate has a thickness of 0.4
mm to 3 mm.

4. The product of claim 1, wherein the carbon fiber reinforced
thermoplastic resin of the sheet material comprises 40% to 65% by volume
of carbon fiber.

5. The product of claim 1, wherein the flat plate comprises a first sheet
material comprising a carbon fiber reinforced thermoplastic resin, and a
second sheet material provided above the first sheet material and
comprising a same thermoplastic resin as a thermoplastic resin included
in the carbon fiber reinforced thermoplastic resin of the first sheet
material; and the metal plate is provided between the first and second
sheet materials.

6. The product of claim 1, wherein the flat plate comprises a first sheet
material comprising the carbon fiber reinforced thermoplastic resin, and
a second sheet material provided above the first sheet material and
comprising the carbon fiber reinforced thermoplastic resin; and the metal
plate is provided between the first and second sheet materials.

7. The product of claim 1, wherein the metal plate further covers at
least part of a side surface of the projection.

8. The product of claim 1, wherein the projection is a rib, a boss, a
claw and/or a shield portion.

9. A method of manufacturing a carbon fiber reinforced shaped product
comprising a flat plate and at least one projection projecting from a
flat surface of the flat plate, the method comprising: placing a sheet
material comprising a carbon fiber reinforced thermoplastic resin into a
die having at least one depression corresponding to the at least one
projection; placing a metal plate on the sheet material to cover a flat
area of the sheet material corresponding to the at least one depression;
and thermally pressing the sheet material against the die along with the
metal plate, and causing part of the carbon fiber reinforced
thermoplastic resin to flow from the sheet material into the depression.

10. The method of claim 9, wherein the die comprises a plurality of
depressions, and the metal plate covers a plurality of flat areas
corresponding to the plurality of depressions.

11. The method of claim 8, wherein the flat plate has a thickness of 0.4
mm to 3 mm.

12. The method of claim 9, wherein the carbon fiber reinforced
thermoplastic resin of the sheet material comprises 40 to 65% by volume
of carbon fiber.

13. The method of claim 9, wherein the placing the sheet material and the
placing the metal plate include placing, into the die, a first sheet
material comprising a carbon fiber reinforced thermoplastic resin,
placing the metal plate on the first sheet material, and placing, onto
the metal plate, a second sheet material comprising a same thermoplastic
resin as a thermoplastic resin included in the carbon fiber reinforced
thermoplastic resin of the first sheet material.

14. The method of claim 9, further comprising the metal plate covering at
least part of a side surface of the projection.

15. The method of claim 9, wherein the projection is a rib, a boss, a
claw and/or a shield portion.

17. The electronic device of claim 16 being a notebook personal computer.

18. The electronic device of claim 17, comprising a main unit housing
and/or a display unit housing, wherein the main unit housing and/or the
display unit housing, or a rib, a boss, a claw or a shield plate
belonging to the main unit housing and/or the display unit housing,
comprises the carbon fiber reinforced shaped product.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application
No. 62/084,850, filed Nov. 26, 2014, the entire contents of which are
incorporated herein by reference.

FIELD

[0002] Embodiments described herein relate generally to a carbon fiber
reinforced shaped product including a metal plate, and a manufacturing
method thereof.

BACKGROUND

[0003] In general, electronic devices, such as computers, personal
computers and information terminals, use shaped products formed of a
carbon fiber reinforced composite, to make them light and rigid. To
realize further light weight of these devices, the shaped products have
been made thinner. In this case, to maintain appropriate rigidity, the
products have thick portions, such as ribs and bosses.

[0004] There is a known method of forming ribs and bosses on a carbon
fiber reinforced shaped composite product including a thermo-setting
resin, by outsert-molding and injection using a thermoplastic resin, and
applying an adhesive to the resultant structure to enhance the adhesion
of the interface between the carbon fiber reinforced composite of the
product and the ribs or bosses. However, a large amount of resin exists
at the interface between the carbon fiber reinforced composite and the
thermoplastic resin forming the ribs or bosses. Therefore, the known
method is disadvantageous in reducing the weight and thickness of the
product.

[0005] Further, a method of forming ribs, bosses and claws simultaneously
with the molding of carbon fiber, using a thermoplastic carbon fiber
reinforced composite has been developed. Since the carbon fiber
reinforced composite has a higher rigidity than other general
thermoplastic resins, it enables shaped products to be made thinner. The
use of the carbon fiber reinforced composite, however, may easily cause
sink marks to occur on counter surfaces.

[0006] As a technique of preventing occurrence of sink marks, a method of,
for example, forming ribs using a reinforced fiber mat, and providing, as
a sink-mark preventing sheet, a foamed sheet having closed cells laid
down above the reinforced fiber mat is known.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A general architecture that implements the various features of the
embodiments will now be described with reference to the drawings. The
drawings and the associated descriptions are provided to illustrate the
embodiments and not to limit the scope of the invention.

[0008] FIG. 1 is a cross-sectional view showing an example of a carbon
fiber reinforced shaped product including a metal plate, according to an
embodiment;

[0009] FIGS. 2A, 2B, 2C and 2D are schematic cross-sectional views for
explaining a process sequence of manufacturing the example of the carbon
fiber reinforced shaped product with the metal plate according to the
embodiment;

[0010] FIGS. 3A, 3B and 3C are schematic cross-sectional views for
explaining another process sequence of manufacturing the example of the
carbon fiber reinforced shaped product with the metal plate according to
the embodiment;

[0011] FIG. 4A is a plan view showing the example of the carbon fiber
reinforced shaped product with the metal plate according to the
embodiment;

[0012] FIG. 4B is a cross-sectional view showing the example of the carbon
fiber reinforced shaped product with the metal plate according to the
embodiment;

[0013] FIG. 5 is a cross-sectional view showing another example of the
carbon fiber reinforced shaped product with the metal plate according to
the embodiment; and

[0014] FIG. 6 is a perspective view of an example of a notebook computer
(PC) as an article provided with a carbon fiber reinforced shaped product
including a metal plate, showing a state in which the display unit of the
PC is open.

DETAILED DESCRIPTION

[0015] Various embodiments will be described hereinafter with reference to
the accompanying drawings. The drawings are merely schematic and are not
to scale.

[0016] FIG. 1 is a cross-sectional view showing an example of a carbon
fiber reinforced shaped product according to the embodiment. A carbon
fiber reinforced shaped product 1 comprises a flat plate 2, at least one
projection 3 and a metal plate 4. The flat plate 2 is formed of a sheet
material containing a carbon fiber reinforced thermoplastic resin, and
has first flat surface 2a and second flat surface 2b. The projection 3
projects from the second flat surface 2a of the flat plate 2. Further,
the projection 3 is formed of the thermoplastic resin from the sheet
material. The metal plate 4 is buried in the flat plate 2. The metal
plate 4 covers a flat surface area corresponding to the at least one
projection 3.

[0017] FIGS. 2A to 2D show a process sequence of manufacturing the carbon
fiber reinforced shaped product according to the embodiment.

[0018] A shape-forming die 110 comprises a first die 111 and a second die
112. The inner surface of the first die 111 is formed flat. The inner
surface of the second die 112 has a cavity 114 for forming a projection.

[0019] The projection-forming cavity 114 is a depression that matches the
shape of the projection 3. The projection 3 may be a shield portion, such
as a rib, a boss, a claw or a shielding plate.

[0020] In a method of manufacturing the carbon fiber reinforced shaped
product, firstly, a sheet material 11 containing the carbon fiber
reinforced thermoplastic resin is placed on the first die 111, as is
shown in FIG. 2A.

[0021] It is sufficient if the carbon fiber reinforced thermoplastic resin
is a thermoplastic resin containing carbon fiber. For instance, the
carbon fiber reinforced thermoplastic resin preferably contains 40% to
65% by volume of carbon fiber in the thermoplastic resin.

[0022] As the carbon fiber, polyacrylonitrile carbon fiber, pitch-based
carbon fiber, rayon-based carbon fiber, etc., can be exemplified.
However, the carbon fiber is not limited to these, but any type of carbon
fiber can be used.

[0023] The carbon fiber can have a length of 100 mm to 500 mm, and can
have any form that includes one-directional continuous fiber,
bidirectional fabric woven by bidirectional fiber, polyaxial fabric woven
by multidirectional fiber, corded fiber, sheet fiber, mat fiber, knitted
fiber, etc.

[0024] As the thermoplastic resin, polypropylene resin, polyester resin,
polyamide resin, polycarbonate resin, phenol resin, phenoxy resin,
polyethylene terephthalate resin, polybutylene terephthalate resin,
polyimide resin, fluorine resin, a copolymer thereof, a degenerative
material thereof, and a resin obtained by blending two or more resins,
can be exemplified. However, the thermoplastic resin is not limited to
these, but any type of thermoplastic resin can be used.

[0025] Secondly, as shown in FIG. 2B, the metal plate 4 is placed on an
area of the sheet material 11 opposing the projection-forming cavity 114.
After that, the first and second dies 111 and 112 are engaged with each
other. By this engagement, the sheet material 11 and the metal plate 4
are received in a shape-forming cavity 113 formed in the die 110.

[0026] As the metal plate, a metal plate of aluminum or an alloy plate of
an aluminum alloy can be exemplified. The thickness of the metal plate
can be selected based on conditions, such as the size of a finished
product including the shaped product, the thickness of the shaped
product, and the place where the shaped product is used. For instance,
the metal plate can have a thickness of 0.03 mm to 0.05 mm. The word
"metal plate" can be replaced with "metal film."

[0027] Subsequently, as shown in FIG. 2C, thermal press molding, where the
second die is pressed against the first die while heat is applied to the
dies, is executed. The heat causes the thermoplastic resin in the sheet
material 11 to flow upward.

[0028] Further thermal pressing causes the thermoplastic resin to flow
into the projection-forming cavity 114 as shown in FIG. 2D. After the
shape-forming cavity 113 and the projection-forming cavity 114 in the
shape-forming die 110 are filled with a plastic resin supplied from the
carbon fiber reinforced thermoplastic resin, application of heat and
pressure is stopped.

[0029] After the temperature of the die 110 is reduced, the resultant
shaped product is detached from the first and second dies. Thus, the
carbon fiber reinforced shaped product including the metal plate is
obtained.

[0030] The flat plate of the thus-produced carbon fiber reinforced shaped
product can have a total thickness of, for example, 0.4 mm to 3 mm.

[0031] The volume of the projection-forming cavity 114 can range from more
than 0% to 50% of the volume of the sheet material 11. For instance, the
volume of the projection-forming cavity 114 can range from more than 0
mm3 to 5000 mm3.

[0032] By virtue of the above manufacturing method, a carbon fiber
reinforced shaped product with less sink marks than in the prior art can
be easily manufactured.

[0033] FIGS. 3A to 3C show another process sequence of manufacturing the
carbon fiber reinforced shaped product of the embodiment.

[0034] As shown in FIG. 3A, a first sheet material 11 containing a carbon
fiber reinforced thermoplastic resin is placed on the first die 111.

[0035] Subsequently, as shown in FIG. 3B, a metal plate 4 is placed on an
area including an area of the first sheet material 11 opposing the
projection-forming cavity 114. Further, a second sheet material 15 is
placed on the metal plate 4.

[0036] The second sheet material 15 may contain a carbon fiber reinforced
thermoplastic resin, may be the carbon fiber reinforced thermoplastic
resin, may contain the same as a thermoplastic resin contained in the
carbon fiber reinforced thermoplastic resin, or may be the same as a
thermoplastic resin contained in the carbon fiber reinforced
thermoplastic resin. Further, the second sheet material 15 can contain
the same as a component of the first sheet material 11. The second sheet
material 15 may be the same as the first sheet material 11 in
component(s). Alternatively, the second sheet material 15 may be the same
as thermoplastic resin contained in the first sheet material 11.

[0037] Further, as the second sheet material 15, a prepreg can be used.
For instance, a commercially available prepreg can be used. As the
commercially available prepreg, Torayca (trademark) prepreg (Toray Inc.),
Tenax (trademark) prepreg (Toho Tenax Co., Ltd.), Pyrofil (trademark)
prepreg (Mitsubishi Rayon Co., Ltd.), etc., are exemplified.

[0038] The second sheet material 15 can have a volume of 15,000 mm3
to 375,000 mm3. The volume of the projection-forming cavity 114 can
be more than 0% to 50% of the volume of the second sheet material 15. For
instance, the volume of the projection-forming cavity 114 can be more
than 0 mm3 to 5000 mm3.

[0039] The first and second dies 111 and 112 are engaged with each other.
By this engagement of these dies, the first sheet material 11, the metal
plate 4 and the second sheet material 15 are received in a shape-forming
cavity 113 formed in the die 110.

[0040] After that, as shown in FIG. 3C, thermal press molding, where the
second die is pressed against the first die while heat is applied to the
dies, is executed. The heat causes the thermoplastic resin in the sheet
material 11 and the plastic resin in the second sheet material 15 are
blended and integrated. The metal plate 4 is buried in the thermoplastic
resin. Further thermal pressing causes the thermoplastic resin to flow
into the projection-forming cavity 114. After the shape-forming cavity
113 and the projection-forming cavity 114 in the shape-forming die 110
are filled with the plastic resin supplied from the carbon fiber
reinforced thermoplastic resin, application of heat and pressure is
stopped.

[0041] After the temperature of the die 110 is reduced, the resultant
shaped product is detached from the first and second dies. Thus, the
carbon fiber reinforced shaped product including the metal plate is
obtained.

[0042] By virtue of the above manufacturing method, a greater amount of
plastic resin can be supplied into the shape-forming cavity 113 and the
projection-forming cavity 114, in addition to the above-described
advantage.

[0043] Referring then to FIGS. 4A, 4B and 5, a description will be given
of yet another example of the carbon fiber reinforced shaped product of
the embodiment.

[0044] FIG. 4A is a plan view showing a carbon fiber reinforced shaped
product example provided with a rib 31 as a first projection, a boss 32
as a second projection, and a claw 33 as a third projection. In FIG. 4A,
the area enclosed by the broken line is where a metal plate 4 is placed.

[0045] FIG. 4B is a cross-sectional view obtained when the carbon fiber
reinforced shaped product 1 of FIG. 4A is viewed along line IVB-IVB of
FIG. 4A. As shown in FIGS. 4A and 4B, in the carbon fiber reinforced
shaped product 1 of the embodiment, the rib 31, the boss 32 and the claw
33 are linearly arranged in this order from one end to the other end. The
rib 31, the boss 32 and the claw 33 substantially perpendicularly project
from the second flat surface of the flat plate 2. As shown in FIG. 4B,
the metal plate 4 is buried in the flat plate 2 to cover a flat area
corresponding to the rib 31, the boss 32 and the claw 33.

[0046] The flat plate 2 and the metal plate 4 contained therein are angled
on the claw (33) side such that their cross section will have an L-shape.

[0047] More specifically, the flat plate 2 is angled at substantially
right angles on the second flat surface side thereof such that it extends
along the axis of the claw 33 to substantially the half position of the
claw 33. Similarly, the metal plate 4 is angled at substantially right
angles on the second flat surface side of the flat plate 2, extending
along the shape of the flat plate 2 along the claw 33 side. The metal
plate 4 covers an area that ranges from the rib (31)-side end to the
distal end of the claw 33 and includes areas corresponding to the rib 31
and the boss 32. Further, the metal plate 4 is angled at substantially
right angles on the second flat surface side of the flat plate 2 such
that it extends along the axis of the claw 33. The distal end of the
angled portion of the metal plate 4 does not project from the flat plate
2.

[0048] The rigidity of the claw 33 can be enhanced by extending the metal
plate 3 along the claw 33.

[0049] FIG. 5 shows another example of the carbon fiber reinforced shaped
product according to the embodiment. FIG. 5 is a cross-sectional view of
the carbon fiber reinforced shaped product 1. The carbon fiber reinforced
shaped product 1 comprises a flat plate 2, a metal plate 4, a shield
portion including two shielding plates 31, and a boss 32.

[0050] The two shielding plates 31 perpendicularly project from the second
flat surface of the flat plate 2 respectively. The two shielding plates
31 can be positioned in respective areas to be shielded.

[0051] The boss 32 is positioned between the two shielding plates 31. The
boss 32 perpendicularly projects from the second flat surface of the flat
plate 2.

[0052] The opposite ends of the metal plate 4 perpendicularly project from
the second flat surface of the flat plate 2 along the outer wall surfaces
of the respective shielding plates 31. The opposite ends of the metal
plate 4 are exposed to the outside to cover at least parts of the outer
wall surfaces of the shielding plates 31.

[0053] In the carbon fiber reinforced shaped product of the embodiment, a
shield portion, such as a shielding plate, can be formed more easily than
in the prior art. Further, by, for example, exposing the metal plate on
the outer wall surfaces of the shielding plates, stable conduction can be
achieved. Also, by imparting a function as a rib and a function as a
shielding plate to a projection, shielding plate(s) can be partially
reduced.

[0054] In accordance with one embodiment, a product including the carbon
fiber reinforced shaped product according to one or more embodiments is
provided. This product includes an electronic device. The electronic
device may be a notebook PC. The embodiment can provide a notebook PC
that includes the carbon fiber reinforced shaped product as, for example,
a housing forming the notebook PC, a member belonging to the housing,
and/or a part of the member belonging to the housing.

[0055] FIG. 6 is a perspective view of an example of a notebook PC as an
article provided with a carbon fiber reinforced shaped product according
to the embodiment, showing a state in which the display unit of the PC is
open.

[0056] A notebook PC 20 shown in FIG. 6 comprises a main unit 21, and a
display unit 22 openably and closably connected to the rear end of the
main unit 21 by a hinge 23.

[0057] The display unit 22 comprises a display housing 221 formed of a
front wall 2211 and a rear wall (not shown), and a display panel 222
received in the display housing 221. The display panel 222 is exposed in
wide opening 2211a formed in the front wall 2211 of the display housing
221.

[0058] The main unit 21 comprises a housing 211 formed of an upper wall
2111 and a lower wall (not shown). A main board (not shown) is installed
in the housing 211.

[0059] A keyboard 24 is mounted on the upper wall 2111 of the main unit
21. The portion (keyboard mounting portion) of the upper wall 2111, in
which the keyboard 24 is mounted, is depressed in the housing 211.

[0060] The portion of the upper wall 2111 positioned in front of the
keyboard mounting portion constitutes left and right palmrests 2111a and
2111b. A touchpad 25 is provided between left and right palmrests 2111a
and 2111b, and is operated by left and right touchpad buttons 26a and
26b. The portion of the upper wall 2111 excluding the touchpad 25 and
touchpad buttons 26a and 26b is formed integral as one body.

[0061] The housing 221 of the display unit and the housing 211 of the main
unit can be made of magnesium or an alloy thereof (for example, AZ91
alloy).

[0062] For instance, the carbon fiber reinforced shaped product of the
embodiment is incorporated in the notebook PC 20 as bosses, ribs, claws
and/or shield portions necessary for constituting the notebook PC 20.
More specifically, it can constitute a boss, a rib, a claw or a shield
portion extending along the inner wall of the housing 211 of the main
unit 21 or the display housing 221 of the display unit 22. It may be also
included in a member belonging to the housing 211 or the display housing
221, for example, in a cover member attached thereto.

[0063] A description will be given of an example.

EXAMPLE

[0064] The lower wall of the main unit housing of the notebook PC, which
includes a boss having a structure as shown in FIG. 1, was produced.

[0065] A first die and a second die, which provide a shape-forming cavity
of a shape corresponding to the lower wall when they are engaged with
each other, were prepared. The second die has a projection-forming cavity
corresponding to the shape of a boss. By thermal press molding using
these dies, the lower wall of the main unit housing of a notebook PC,
which has a boss, was produced. The lower wall is an example of the
carbon fiber reinforced shaped product of the embodiment, which has a
flat plate, a boss formed of a projection on the second flat surface of
the flat plate, and a metal plate buried in the flat plate.

[0066] The thus-produced carbon fiber reinforced shaped product had no
sink marks on the second flat surface of the flat plate opposing the
boss.

[0067] Except for the lower wall, the notebook PC was produced by a known
technique.

[0068] The above-described manufacturing method can provide a carbon fiber
reinforced shaped product according to the embodiment. The carbon fiber
reinforced shaped product of the embodiment comprises a metal plate that
covers a flat area corresponding to a projection. Accordingly, a carbon
fiber reinforced shaped product, in which no sink marks are formed on the
second flat surface opposing the projection, can be acquired. Further,
the metal plate buried in the flat plate imparts a higher rigidity to the
carbon fiber reinforced shaped product. This advantage is brought to any
of small, medium-size and large electronic devices. Since sink marks can
be avoided by a small number of structural elements to thereby provide
highly rigid products, the embodiment is especially advantageous to small
electronic devices.

[0069] While certain embodiments have been described, these embodiments
have been presented by way of example only, and are not intended to limit
the scope of the inventions. Indeed, the novel embodiments described
herein may be embodied in a variety of other forms; furthermore, various
omissions, substitutions and changes in the form of the embodiments
described herein may be made without departing from the spirit of the
inventions. The accompanying claims and their equivalents are intended to
cover such forms or modifications as would fall within the scope and
spirit of the inventions.